#include <stdlib.h>
#include <stdio.h>

#include "defs.h"


/* TABLE_SIZE is the number of entries in the symbol table. */
/* TABLE_SIZE must be a power of two.			    */

#define	TABLE_SIZE 1024


bucket **symbol_table;
bucket *first_symbol;
bucket *last_symbol;


int hash(const char *name)
{
	const char *s;
	int c, k;

	assert(name && *name);
	s = name;
	k = *s;
	while (c = *++s)
		k = (31 * k + c) & (TABLE_SIZE - 1);

	return (k);
}


bucket *make_bucket(const char *name)
{
	bucket *bp;

	assert(name);
	bp = (bucket *) MALLOC(sizeof(bucket));
	if (bp == 0)
		no_space();
	bp->link = 0;
	bp->next = 0;
	bp->name = MALLOC(strlen(name) + 1);
	if (bp->name == 0)
		no_space();
	bp->tag = 0;
	bp->value = UNDEFINED;
	bp->index = 0;
	bp->prec = 0;
	bp->class = UNKNOWN;
	bp->assoc = TOKEN;
	bp->lineno = lineno;

	if (bp->name == 0)
		no_space();
	strcpy(bp->name, name);

	return (bp);
}


bucket *lookup(const char *name)
{
	bucket *bp, **bpp;

	bpp = symbol_table + hash(name);
	bp = *bpp;

	while (bp)
	{
		if (strcmp(name, bp->name) == 0)
			return (bp);
		bpp = &bp->link;
		bp = *bpp;
	}

	*bpp = bp = make_bucket(name);
	last_symbol->next = bp;
	last_symbol = bp;

	return (bp);
}

void create_symbol_table(void)
{
	int i;
	bucket *bp;

	symbol_table = (bucket **) MALLOC(TABLE_SIZE * sizeof(bucket *));
	if (symbol_table == 0)
		no_space();
	for (i = 0; i < TABLE_SIZE; i++)
		symbol_table[i] = 0;

	bp = make_bucket("error");
	bp->index = 1;
	bp->class = TERM;

	first_symbol = bp;
	last_symbol = bp;
	symbol_table[hash("error")] = bp;
}

void free_symbol_table(void)
{
	FREE(symbol_table);
	symbol_table = 0;
}

void free_symbols(void)
{
	bucket *p, *q;

	for (p = first_symbol; p; p = q)
	{
		q = p->next;
		FREE(p);
	}
}
